Issue 4234 - Migrate Discourse to a Docker-based setup

The changes here have been finalized, still expect Ubuntu precise however.

Repository: hg.adblockplus.org/infrastructure

[Wladimir Palant, 2016-07-08 15:46:38]

https://codereview.adblockplus.org/29347356/diff/29347379/hiera/roles/intrafo...
File hiera/roles/intraforumserver.yaml (right):

https://codereview.adblockplus.org/29347356/diff/29347379/hiera/roles/intrafo...
hiera/roles/intraforumserver.yaml:14: share_links: ""
This setting is new, we didn't have it in our previous version - I disabled
sharing posts.

https://codereview.adblockplus.org/29347356/diff/29347379/hiera/roles/intrafo...
hiera/roles/intraforumserver.yaml:18: allow_new_registrations: "t"
For some reason, this is necessary even for creating a Google OAuth2 account.

https://codereview.adblockplus.org/29347356/diff/29347379/hiera/roles/intrafo...
hiera/roles/intraforumserver.yaml:22: enable_instagram_logins: "f"
This setting is new, we didn't have it in our previous version.

https://codereview.adblockplus.org/29347356/diff/29347379/modules/discourse/m...
File modules/discourse/manifests/init.pp (right):

https://codereview.adblockplus.org/29347356/diff/29347379/modules/discourse/m...
modules/discourse/manifests/init.pp:27: ensure => present,
Note that this installs git 1.7.9.5 which is lower than git 1.8.0 required by
Discourse. That's the reason behind --skip-prereqs flag below - doesn't actually
seem to affect anything, it's not clear why the git version on the host matters.

https://codereview.adblockplus.org/29347356/diff/29347379/modules/discourse/m...
modules/discourse/manifests/init.pp:75: subscribe => Exec['rebuild'],
I still need to verify that this is working correctly and Discourse is started
under all circumstances.

[Wladimir Palant, 2016-07-10 16:42:13]

I implemented a few minor changes, the patch is final now. The only uncertainty
is the operating system - currently it expects Ubuntu Precise with an updated
kernel, but running on Debian Jesse should work just as well of course.

Note that I outlined the upgrade strategy in the issue.

https://codereview.adblockplus.org/29347356/diff/29347379/modules/discourse/m...
File modules/discourse/manifests/init.pp (right):

https://codereview.adblockplus.org/29347356/diff/29347379/modules/discourse/m...
modules/discourse/manifests/init.pp:75: subscribe => Exec['rebuild'],
On 2016/07/08 15:46:38, Wladimir Palant wrote:
> I still need to verify that this is working correctly and Discourse is started
> under all circumstances.

I verified that the container will always get started automatically, even on a
reboot. Still, I'm leaving the start call here just in case.

https://codereview.adblockplus.org/29347356/diff/29347488/Vagrantfile
File Vagrantfile (right):

https://codereview.adblockplus.org/29347356/diff/29347488/Vagrantfile#newcode17
Vagrantfile:17: config.vm.box_url =
'http://nitron-vagrant.s3-website-us-east-1.amazonaws.com/vagrant_ubuntu_12.04.3_amd64_virtualbox.box'
If we get to run on Debian Jesse soon then this can be removed - currently the
assumption is that the kernel will be updated on the existing host before
deployment.

[Wladimir Palant, 2016-07-12 17:00:27]

I updated to a newer Discourse release even though it's still beta - the phpBB
importer got quite a few improvements. I also increased the amount of memory in
the VM to 4GB. While that doesn't really match our current setup, neither does
the swap space in the predefined image. With merely 1GB of memory available
Discourse installation will inevitably run out of memory, and even if you add
swap space it will be extremely slow.

[mathias, 2016-07-13 17:48:03]

Very promising ;-)

https://codereview.adblockplus.org/29347356/diff/29347713/Vagrantfile
File Vagrantfile (right):

https://codereview.adblockplus.org/29347356/diff/29347713/Vagrantfile#newcode15
Vagrantfile:15: if host_name == 'server10'
(That is not beautiful but fine for now due to our intention to improve on node
classification and provide a more general Docker integration in the very near
future.)

https://codereview.adblockplus.org/29347356/diff/29347713/modules/discourse/m...
File modules/discourse/manifests/init.pp (right):

https://codereview.adblockplus.org/29347356/diff/29347713/modules/discourse/m...
modules/discourse/manifests/init.pp:46: onlyif => "test ! -d /var/discourse/.hg"
Using exec resource parameter "unless" is more straightforward than negation
with "onlyif", in general, and in this case one may even prefer using parameter
"creates" instead (assuming the explicit test for being a directory having not
much more value than a general test for existence).

[Wladimir Palant, 2016-07-13 18:01:13]

https://codereview.adblockplus.org/29347356/diff/29347713/modules/discourse/m...
File modules/discourse/manifests/init.pp (right):

https://codereview.adblockplus.org/29347356/diff/29347713/modules/discourse/m...
modules/discourse/manifests/init.pp:46: onlyif => "test ! -d /var/discourse/.hg"
On 2016/07/13 17:48:03, mathias wrote:
> Using exec resource parameter "unless" is more straightforward than negation
> with "onlyif", in general, and in this case one may even prefer using
parameter
> "creates" instead (assuming the explicit test for being a directory having not
> much more value than a general test for existence).

The more important question is whether we should even use our copy of the
repository here given that Discourse assumes Git (particularly to verify that
the discourse_docker checkout is up to date) and will check out several
repositories from GitHub within the container anyway (meaning: if GitHub is down
then it won't work regardless).

[Wladimir Palant, 2016-10-12 13:18:29]

Updated the patch again, just in case. This is cloning from GitHub rather than
our copy now. Also, I've updated to Discourse 1.6.4 which happens to be current
by now.

[f.nicolaisen, 2017-01-06 17:18:50]

On 2016/10/12 13:18:29, Wladimir Palant wrote:
> Updated the patch again, just in case. This is cloning from GitHub rather than
> our copy now. Also, I've updated to Discourse 1.6.4 which happens to be
current
> by now.

This review can be closed as we've transferred the work to new commits, ref:
https://issues.adblockplus.org/ticket/4234#comment:11

We also upgraded to Discourse 1.6.10 btw, that is the latest stable version.